Along with rapid development of modern technologies, the Internet has been widely applied to various fields. Internet Protocol version 4 (IPv4) adopted at the present stage cannot meet requirements of development of times, since defined IPv4 addresses have been completely allocated and many countries and regions are still confronted with the problem of shortage of IPv4 addresses. It is an inevitable trend to replace IPv4 with a new-generation address protocol Internet Protocol version 6 (IPv6), but transition from IPv4 to IPv6 will be a long and gradual process. In such a process, many types of IPv6 transition technologies emerge, mainly including:
an IPv6/IPv4 dual-stack technology: a dual-stack node adopts an IPv4 protocol stack when communicating with an IPv4 node, and adopts an IPv6 protocol stack when communicating with an IPv6 node;
a tunneling technology: the technology can implement communication connection between two IPv6 stations through an IPv4 network and implement communication connection between two IPv4 stations through an IPv6 network; and
an IPv4/IPv6 protocol conversion technology: the technology enables mutual access between an IPv4 network and an IPv6 network.
At present, a plurality of workgroups of the Internet Engineering Task Force (IETF), the most authoritative technology standardization organization in global Internet, are discussing technologies for IPv6 transition, and a current main solution involves: technological forms such as Network Address Translation IPv4-IPv4 (NAT44), NAT IPv4-IPv4-IPv4 (NAT444), Dual-Stack Lite (DS-Lite), Light Weight 4over6, Mapping of Address and Port with Encapsulation (MAP), NAT IPv6-IPv4 (NAT64), an IPv6 Provider Edge (6PE) and IV-VI (Roman numerals 4-6, representative of IPv4-IPv6 stateless translation) (WI).
However, each IPv6 transition technology in a related technology only solves an IPv6 transition problem in a specific scenario, and cannot run in a unified manner. Moreover, efforts at unified deployment of IPv6 technologies are all made on the basis of a Software Defined Network (SDN). The SDN structure is a novel network innovation structure, and the core technology of the SDN separates a control plane and a data plane of network equipment, thereby implementing flexible control over network traffic and providing a good platform for innovation of a core network and an application.
Fusing an IPv6 transition technology and an SDN technology solves problems of unified deployment and management of IPv6, but also has many disadvantages, for example, sessions are required to be maintained in most of IPv6 transition technologies in the related technology. The so called session is a mapping entry of and intranet address and port and extranet address and port generated by access of a user to an extranet. FIG. 1 is a structure diagram of an SDN and IPv6 transition fusion technology in the related technology. As shown in FIG. 1, the SDN and IPv6 transition fusion technology has the following disadvantages.
In the SDN and IPv6 transition fusion technology provided by the related art, a first packet of a user connected to the Internet is sent to an SDN controller for the SDN controller to generate a session through forwarding equipment. Since the SDN controller is required to manage a large number of forwarding equipment, such a manner may require the SDN controller to maintain a large number of sessions and make a large part of SDN controller performance occupied. For example, the SDN controller controls 10,000 pieces of forwarding equipment, each piece of forwarding equipment maximally supports accommodation of 10 millions of sessions, and if an SDN structure is adopted, the SDN controller is required to support 100 billions of sessions, which brings enormous pressure to the SDN controller. In addition, the SDN controller is also responsible for managing other services, such as network topology calculation and flow table transmission, so that higher storage and calculation pressure may be brought after an IPv6 transition technology is fused.
Moreover, the first packet of the user connected to the Internet is sent to the SDN controller through the forwarding equipment, and high traffic can be generated between the forwarding equipment and the SDN controller to cause network congestion. For example, the forwarding equipment supports creation of 1 million sessions per second, each SDN controller controls 10,000 pieces of forwarding equipment, then 10 billions of data packets are generated by transmission between the forwarding equipment and the SDN controller per second, and it is impossible for the SDN controller to complete receiving and processing the data packets.
Therefore, there exist the problems of incapability of a network system in effective running during fusion with an IPv6 transition technology and incapability in effective implementation of unified deployment of the IPv6 transition technology in the related technology.